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Ausiello P, Ciaramella S, Fabianelli A, Gloria A, Martorelli M, Lanzotti A, Watts DC. Mechanical behavior of bulk direct composite versus block composite and lithium disilicate indirect Class II restorations by CAD-FEM modeling. Dent Mater 2017; 33:690-701. [DOI: 10.1016/j.dental.2017.03.014] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Revised: 03/17/2017] [Accepted: 03/17/2017] [Indexed: 11/28/2022]
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Effect of Artificial Aging Protocols on Surface Gloss of Resin Composites. Int J Dent 2017; 2017:3483171. [PMID: 28611843 PMCID: PMC5458377 DOI: 10.1155/2017/3483171] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2016] [Revised: 03/14/2017] [Accepted: 05/02/2017] [Indexed: 12/03/2022] Open
Abstract
The purpose of this study was to evaluate the effect of aging protocols on surface gloss of composites. Cylindrical resin composite specimens (6 mm in diameter, 1 mm thick) were fabricated and divided into three groups (N = 60): microfilled (MiFi), nanohybrid (NaHy), and nanofilled (NaFi). Specimens were distributed into four aging subgroups: thermocycling (5° to 55°C, 15,000 cycles); ethanol immersion (15 days); brushing (10,750 cycles); and light aging (216 h). Surface gloss readings (Novo-Curve, Rhopoint TM, England) were performed at baseline (R0) and after every one-third of aging protocols (R1 to R3). Data were submitted to one-way repeated measures ANOVA and Tukey's test (5%). Overall, surface gloss alterations were detected over time (p < 0.001). Thermocycling reduced surface gloss, except for NaHy. Ethanol immersion resulted in surface gloss reduction after R1 for MiFi and NaFi, while reduction after R1 and R2 was detected for NaHy. For brushing, gloss reduction was detected after R1 and R3 for all composites. For light aging, gloss was reduced after R1 and R2 for MiFi and NaFi, while a reduction only after R1 was detected for NaHy. The studied aging protocols affect surface gloss differently, being material and aging therapy dependent. In general, the surface gloss is reduced with aging.
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Karakis D, Yıldırım-Bicer AZ, Dogan A, Koralay H, Cavdar S. Effect of self and dual-curing on degree of conversion and crosslink density of dual-cure core build-up materials. J Prosthodont Res 2017; 61:210-216. [DOI: 10.1016/j.jpor.2016.05.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 04/22/2016] [Accepted: 05/26/2016] [Indexed: 11/30/2022]
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Lee MJ, Kim MJ, Kwon JS, Lee SB, Kim KM. Cytotoxicity of Light-Cured Dental Materials according to Different Sample Preparation Methods. MATERIALS 2017; 10:ma10030288. [PMID: 28772647 PMCID: PMC5503327 DOI: 10.3390/ma10030288] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Revised: 03/06/2017] [Accepted: 03/09/2017] [Indexed: 11/16/2022]
Abstract
Dental light-cured resins can undergo different degrees of polymerization when applied in vivo. When polymerization is incomplete, toxic monomers may be released into the oral cavity. The present study assessed the cytotoxicity of different materials, using sample preparation methods that mirror clinical conditions. Composite and bonding resins were used and divided into four groups according to sample preparation method: uncured; directly cured samples, which were cured after being placed on solidified agar; post-cured samples were polymerized before being placed on agar; and “removed unreacted layer” samples had their oxygen-inhibition layer removed after polymerization. Cytotoxicity was evaluated using an agar diffusion test, MTT assay, and confocal microscopy. Uncured samples were the most cytotoxic, while removed unreacted layer samples were the least cytotoxic (p < 0.05). In the MTT assay, cell viability increased significantly in every group as the concentration of the extracts decreased (p < 0.05). Extracts from post-cured and removed unreacted layer samples of bonding resin were less toxic than post-cured and removed unreacted layer samples of composite resin. Removal of the oxygen-inhibition layer resulted in the lowest cytotoxicity. Clinicians should remove unreacted monomers on the resin surface immediately after restoring teeth with light-curing resin to improve the restoration biocompatibility.
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Affiliation(s)
- Myung-Jin Lee
- Department and Research Institute of Dental Biomaterials and Bioengineering, Yonsei University College of Dentistry, Seoul 03722, Korea.
- Brain Korea 21 PLUS Project, Yonsei University College of Dentistry, Seoul 03722, Korea.
| | - Mi-Joo Kim
- Department and Research Institute of Dental Biomaterials and Bioengineering, Yonsei University College of Dentistry, Seoul 03722, Korea.
| | - Jae-Sung Kwon
- Department and Research Institute of Dental Biomaterials and Bioengineering, Yonsei University College of Dentistry, Seoul 03722, Korea.
| | - Sang-Bae Lee
- Dental Device Testing and Evaluation Center, Yonsei University College of Dentistry, Seoul 03722, Korea.
| | - Kwang-Mahn Kim
- Department and Research Institute of Dental Biomaterials and Bioengineering, Yonsei University College of Dentistry, Seoul 03722, Korea.
- Brain Korea 21 PLUS Project, Yonsei University College of Dentistry, Seoul 03722, Korea.
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de Oliveira DCRS, Rovaris K, Hass V, Souza-Júnior EJ, Haiter-Neto F, Sinhoreti MAC. Effect of low shrinkage monomers on physicochemical properties of dental resin composites. Braz Dent J 2017. [PMID: 26200152 DOI: 10.1590/0103-6440201300401] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
UNLABELLED The aim of this study was to evaluate the effect of low shrinkage monomers on physicochemical properties of dental resin composites. Two low shrinkage resin composites: one with a crosslink branching monomer (Kalore, GC Corp) and a novel monomer (Venus Diamond, Heraeus Kulzer) were compared to a conventional resin composite formulation (Filtek Z250, 3M/ESPE). The volumetric shrinkage was evaluated by µCT analysis (n=5) and the physicochemical properties by degree of C=C conversion (DC), flexural strength (FS) and Young's modulus (YM) (n=10). All samples were light cured by a LED device (Radii, SDI) with 16 J/cm2. The results were analysed by one-way ANOVA and Tukey test for multiple comparisons (α=0.05). No statistical difference was found between µCT shrinkage values to Kalore (1.8%) and Venus Diamond (1.7%) (p≥0.05); Z250 presented statistical highest shrinkage value (2.0%). Kalore presented higher statistical DC (60.8%) than Venus Diamond (49.5%) and Z250 (49.6%). No statistical difference was found between FS or YM properties to Venus Diamond and Z250; Kalore presented statistical lowest FS and YM properties (p≥0.05). CONCLUSION Using novel monomers seem to reduce polymerization shrinkage without affecting the physicochemical properties evaluated of resin composites rather than using crosslink branching monomers.
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Affiliation(s)
| | - Karla Rovaris
- Department of Dental Radiology, Piracicaba Dental School, Universidade Estadual de Campinas, Piracicaba, SP, Brasil
| | - Viviane Hass
- Department of Restorative Dentistry, Universidade Estadual de Ponta Grossa, Ponta Grossa, PR, Brasil
| | - Eduardo José Souza-Júnior
- Department of Restorative Dentistry, Piracicaba Dental School, Universidade Estadual de Campinas, Piracicaba, SP, Brasil
| | - Francisco Haiter-Neto
- Department of Dental Radiology, Piracicaba Dental School, Universidade Estadual de Campinas, Piracicaba, SP, Brasil
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Križnar I, Seme K, Fidler A. Bacterial microleakage of temporary filling materials used for endodontic access cavity sealing. J Dent Sci 2016; 11:394-400. [PMID: 30895003 PMCID: PMC6395255 DOI: 10.1016/j.jds.2016.06.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Revised: 06/03/2016] [Indexed: 11/18/2022] Open
Abstract
Background/purpose Providing a tight coronal seal is key for the success of endodontic treatment, therefore the study aimed to assess bacterial microleakage of materials used for short- and long-term temporization. Materials and methods One hundred and twenty-eight human upper-third molars were divided into six experimental groups (n = 20) and two control groups: negative (n = 4) and positive (n = 4). The standardized access cavities were prepared and filled with: (1) Cavit; (2) Fuji II LC; (3) Fuji IX; (4) Voco Clip; (5) AdheSE and Tetric EvoCeram; (6) Excite and Tetric EvoCeram. The crown of each tooth was sectioned to obtain 5.5-mm-high disks, which were assembled in a standard setup for bacterial microleakage studies using Streptococcus mutans. The monitoring lasted 90 days. Kaplan-Meier survival analysis was performed. Results The lowest amount of leaking samples was found in AdheSE and Tetric EvoCeram (31.3%), Cavit (33.3%), and Excite and Tetric EvoCeram groups (35.3%), followed by Fuji II LC (66.7%), Voco Clip (83.3%). and Fuji IX (88.2%) groups. According to the day of microleakage, materials could be classified in three groups with statistically significant differences (P < 0.05). In the first group were Cavit (70 days), AdheSE and Tetric EvoCeram (68 days), and Excite and Tetric EvoCeram (65 days), in the second group were Voco Clip (44 days) and Fuji II LC (43 days), and in the third group was Fuji IX (21 days). Conclusion None of the tested materials were able to completely prevent bacterial microleakage. Adhesively bonded composites and Cavit offer better sealing compared with glass ionomer cements, resin modified glass ionomer cements, and composites without the use of an adhesive system.
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Affiliation(s)
- Igor Križnar
- Department for Dental Diseases and Morphology of Dental Organ, Faculty of Medicine, University of Ljubljana, Vrazov trg 2, 1000 Ljubljana, Slovenia
- Corresponding author. Department for Dental Diseases and Morphology of Dental Organ, Faculty of Medicine, University of Ljubljana, Vrazov trg 2, 1000 Ljubljana, Slovenia.
| | - Katja Seme
- Institute of Microbiology and Immunology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia
| | - Aleš Fidler
- Department for Dental Diseases and Morphology of Dental Organ, Faculty of Medicine, University of Ljubljana, Vrazov trg 2, 1000 Ljubljana, Slovenia
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Öztürk-Bozkurt F, Toz T, Kara-Tuncer A, Gözükara-Bağ H, Özcan M. Clinical Evaluation of Silorane and Nano-hybrid Resin Composite Restorations in Class II Cavities up to 3 Years. Oper Dent 2016; 41:599-606. [DOI: 10.2341/15-259-c] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
SUMMARY
In this study, the clinical performance of a silorane-based resin composite (SC) vs a nano-hybrid resin composite (NHC) was evaluated in Class II cavities. From January 2012 to February 2013, a total of 29 patients (eight men, 21 women; mean age, 24 ± 5 years) received 29 pairs of restorations using both SC (Filtek Silorane, 3M ESPE) and NHC (Filtek Z550, 3M ESPE) materials. Patients were followed until February 2015. One operator performed all restorations using the corresponding adhesive resins according to the manufacturers' instructions. Two calibrated independent examiners evaluated the restorations at one week, six months, and then annually using the modified United States Public Health Service (USPHS) criteria for anatomic form, marginal adaptation, color match, surface roughness, marginal discoloration, secondary caries, and postoperative sensitivity. Changes in the USPHS parameters were analyzed with the McNemar test (α=0.05). The mean observation period was 31.2 months. Marginal adaptation was the only parameter that showed a significant difference and was worse for SC than NHC (p=0.012). At the final recall, 17 restorations from the SC group and five from the NHC group received a score of 1 (explorer catches). These scores were significantly different between baseline and final recall for SC (p<0.001) but not for NHC (p>0.05). Both NHC and SC performed similarly in Class II restorations up to three years except for marginal adaptation, for which the latter demonstrated significant deterioration at the final recall compared with baseline.
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Affiliation(s)
- F Öztürk-Bozkurt
- Funda Öztürk-Bozkurt, DDS, PhD, assistant professor, Istanbul Medipol University, School of Dentistry, Department of Restorative Dentistry, Istanbul, Turkey
| | - T Toz
- Tuğba Toz, DDS, PhD, assistant professor, Istanbul Medipol University, School of Dentistry, Department of Restorative Dentistry, Istanbul, Turkey
| | | | | | - M Özcan
- Mutlu Özcan, DrMedDent, PhD, professor, University of Zurich, Center for Dental and Oral Medicine, Dental Materials Unit, Clinic for Fixed and Removable Prosthodontics and Dental Materials Science, Zurich, Switzerland
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Local deformation fields and marginal integrity of sculptable bulk-fill, low-shrinkage and conventional composites. Dent Mater 2016; 32:1441-1451. [DOI: 10.1016/j.dental.2016.09.011] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Revised: 06/17/2016] [Accepted: 09/03/2016] [Indexed: 11/24/2022]
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Roedel L, Bednarzig V, Belli R, Petschelt A, Lohbauer U, Zorzin J. Self-adhesive resin cements: pH-neutralization, hydrophilicity, and hygroscopic expansion stress. Clin Oral Investig 2016; 21:1735-1741. [PMID: 27664153 DOI: 10.1007/s00784-016-1947-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 08/23/2016] [Indexed: 10/21/2022]
Abstract
OBJECTIVES The objective of the study was to investigate the relationship between pH-neutralization, hydrophilicity, and free hygroscopic expansion stress of self-adhesive resin cements (SARCs) after storage in artificial saliva. MATERIALS AND METHODS The SARCs RelyX Unicem Automix 2 (RX2, 3 M ESPE), iCEM (iCEM, Heraeus) and Maxcem Elite (MCE, Kerr) were under investigation in this study. Cylinders (height × diameter, 6 × 4mm) were prepared from each material and stored in artificial saliva (7d at 37 °C). Cylinder height was measured at baseline and after 7 days. After storage, the compression modulus was measured to calculate the free hygroscopic expansion stress. For pH-neutralization and hydrophilicity assessment, disks (height × diameter, 1 × 1.5 mm) were prepared, covered with electrolyte, and monitored over 24 h at 37 °C. Hydrophilicity was assessed using the static sessile drop technique at baseline and at different time intervals up to 24 h. Data were analyzed using one-way ANOVA and post hoc Student-Newman-Keuls test (S-N-K, α = 0.05). RESULTS After 24 h, RX2 (pH24h 4.68) had a significantly higher (p < 0.05) pH-value than MCE (pH24h 4.2) and iCEM (pH24h 3.23). iCEM showed the significantly highest hydrophilicity (p < 0.05) after 24 h (θ24h 85.02°), while MCE resulted lower (θ24h 113.01°) in comparison with RX2 (θ24h 108.11°). The resulting hygroscopic expansion stress of iCEM (29.15 MPa) was significantly higher (p < 0.05) compared to RX2 (14.5 MPa) and MCE (21.02 MPa). CONCLUSIONS The material with lowest pH-neutralization capacity displayed higher hydrophilicity after 24 h and higher hygroscopic expansion stress after 7 days compared to those with high pH-neutralization. CLINICAL SIGNIFICANCE Remnant hydrophilicity due to low pH-neutralization of SARCs could lead to cement interface stress build-up and long-term failure of silicate ceramic restorations.
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Affiliation(s)
- Lena Roedel
- Dental Clinic 1-Operative Dentistry and Periodontology, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Glückstr. 11, 91054, Erlangen, Germany
| | - Vera Bednarzig
- Dental Clinic 1-Operative Dentistry and Periodontology, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Glückstr. 11, 91054, Erlangen, Germany
| | - Renan Belli
- Dental Clinic 1-Operative Dentistry and Periodontology, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Glückstr. 11, 91054, Erlangen, Germany
| | - Anselm Petschelt
- Dental Clinic 1-Operative Dentistry and Periodontology, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Glückstr. 11, 91054, Erlangen, Germany
| | - Ulrich Lohbauer
- Dental Clinic 1-Operative Dentistry and Periodontology, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Glückstr. 11, 91054, Erlangen, Germany
| | - José Zorzin
- Dental Clinic 1-Operative Dentistry and Periodontology, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Glückstr. 11, 91054, Erlangen, Germany.
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da Veiga AMA, Cunha AC, Ferreira DMTP, da Silva Fidalgo TK, Chianca TK, Reis KR, Maia LC. Longevity of direct and indirect resin composite restorations in permanent posterior teeth: A systematic review and meta-analysis. J Dent 2016; 54:1-12. [PMID: 27523636 DOI: 10.1016/j.jdent.2016.08.003] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Revised: 05/13/2016] [Accepted: 08/10/2016] [Indexed: 12/20/2022] Open
Abstract
OBJECTIVES The aim of this systematic review and meta-analysis was to assess the differences in clinical performance in direct and indirect resin composite restorations in permanent posterior teeth. SOURCES PubMed, the Cochrane Library, Web of Science, Scopus, LILACS, BBO, ClinicalTrials.gov and SiGLE were searched without restrictions. STUDY SELECTION We included randomized clinical trials (RCTs) that compared the clinical performance of direct and indirect resin composite restorations in Class I and Class II cavities in permanent teeth, with at least two years of follow-up. The risk of bias tool suggested by Cochrane Collaboration was used for quality assessment. DATA After duplicate removal, 912 studies were identified. Twenty fulfilled the inclusion criteria after the abstract screening. Two articles were added after a hand search of the reference list of included studies. After examination, nine RCTs were included in the qualitative analysis and five were considered to have a 'low' risk of bias. The overall risk difference in longevity between direct and indirect resin composite restorations in permanent posterior teeth (p>0.05) at five-year follow-up was 1.494 [0.893-2.500], and regardless of the type of tooth restored, that of molar and premolars was 0.716 [0.177-2.888] at three-year follow-up. CONCLUSIONS Based on the findings, there was no difference in longevity of direct and indirect resin composite restorations regardless of the type of material and the restored tooth. CLINICAL SIGNIFICANCE Contemporary dentistry is based on minimally invasive restorations. Any indication of a less conservative technique must have unquestionable advantages. In vitro and in vivo studies reveal contradictory evidence of the clinical performance of direct and indirect resin composite restorations in posterior teeth. Thus this study clarified this doubt.
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Affiliation(s)
- Ana Maria Antonelli da Veiga
- Department of Prosthodontics and Dental Materials, Federal University of Rio de Janeiro, Av. Carlos Chagas Filho, 373, Prédio do CCS, Bloco K, Ilha da Cidade Universitária, Rio de Janeiro, Brazil
| | - Amanda Carneiro Cunha
- Department of Pediatric Dentistry and Orthodontics, Federal University of Rio de Janeiro, Av. Carlos Chagas Filho, 373, Prédio do CCS, Bloco K, Ilha da Cidade Universitária, Rio de Janeiro, Brazil
| | - Daniele Masterson Tavares Pereira Ferreira
- Center of Health Science, Federal University of Rio de Janeiro, Av. Carlos Chagas Filho, 373, Prédio do CCS, Bloco I, Ilha da Cidade Universitária, Rio de Janeiro, Brazil
| | - Tatiana Kelly da Silva Fidalgo
- Department of Pediatric Dentistry and Orthodontics, Federal University of Rio de Janeiro, Av. Carlos Chagas Filho, 373, Prédio do CCS, Bloco K, Ilha da Cidade Universitária, Rio de Janeiro, Brazil
| | - Thomaz Kauark Chianca
- Department of Pediatric Dentistry and Orthodontics, Federal University of Rio de Janeiro, Av. Carlos Chagas Filho, 373, Prédio do CCS, Bloco K, Ilha da Cidade Universitária, Rio de Janeiro, Brazil
| | - Kátia Rodrigues Reis
- Department of Prosthodontics and Dental Materials, Federal University of Rio de Janeiro, Av. Carlos Chagas Filho, 373, Prédio do CCS, Bloco K, Ilha da Cidade Universitária, Rio de Janeiro, Brazil
| | - Lucianne Cople Maia
- Department of Pediatric Dentistry and Orthodontics, Federal University of Rio de Janeiro, Av. Carlos Chagas Filho, 373, Prédio do CCS, Bloco K, Ilha da Cidade Universitária, Rio de Janeiro, Brazil.
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Komada W, Inagaki T, Ueda Y, Omori S, Hosaka K, Tagami J, Miura H. Influence of water immersion on the mechanical properties of fiber posts. J Prosthodont Res 2016; 61:73-80. [PMID: 27324293 DOI: 10.1016/j.jpor.2016.05.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2015] [Revised: 05/09/2016] [Accepted: 05/26/2016] [Indexed: 11/30/2022]
Abstract
PURPOSE The purpose of this study was to evaluate the influence of water immersion on the mechanical properties of three kinds of glass fiber posts and the fracture resistance of structures using resin composites with glass fiber posts. METHODS Each post was divided into three groups; a control group and two water immersion groups (30 and 90 days). Flexural strength was determined by three-point bending test. Each structure was divided into two groups; a control group and a water immersion group for 30 days. The fracture strength of structures was determined by a static loading test. RESULTS In the flexural strength, two kinds of post in water immersion groups showed lower values than control groups. In the fracture strength, two kinds of structures in water immersion group showed lower values than control groups. CONCLUSION The prefabricated glass fiber posts and structures using resin composites with glass fiber posts were affected by water immersion.
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Affiliation(s)
- Wataru Komada
- Fixed Prosthodontics, Department of Restorative Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, Japan.
| | - Tasuku Inagaki
- Fixed Prosthodontics, Department of Restorative Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, Japan.
| | - Yoji Ueda
- Fixed Prosthodontics, Department of Restorative Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, Japan.
| | - Satoshi Omori
- Fixed Prosthodontics, Department of Restorative Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, Japan.
| | - Keiichi Hosaka
- Cariology and Operative Dentistry, Department of Restorative Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, Japan.
| | - Junji Tagami
- Cariology and Operative Dentistry, Department of Restorative Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, Japan.
| | - Hiroyuki Miura
- Fixed Prosthodontics, Department of Restorative Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, Japan.
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Polymerization shrinkage kinetics and shrinkage-stress in dental resin-composites. Dent Mater 2016; 32:998-1006. [PMID: 27240744 DOI: 10.1016/j.dental.2016.05.006] [Citation(s) in RCA: 117] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Revised: 05/11/2016] [Accepted: 05/13/2016] [Indexed: 11/23/2022]
Abstract
OBJECTIVES To investigate a set of resin-composites and the effect of their composition on polymerization shrinkage strain and strain kinetics, shrinkage stress and the apparent elastic modulus. METHODS Eighteen commercially available resin-composites were investigated. Three specimens (n=3) were made per material and light-cured with an LED unit (1200mW/cm(2)) for 20s. The bonded-disk method was used to measure the shrinkage strain and Bioman shrinkage stress instrument was used to measure shrinkage stress. The shrinkage strain kinetics at 23°C was monitored for 60min. Maximum strain and stress was evaluated at 60min. The shrinkage strain rate was calculated using numerical differentiation. RESULTS The shrinkage strain values ranged from 1.83 (0.09) % for Tetric Evoceram (TEC) to 4.68 (0.04) % for Beautifil flow plus (BFP). The shrinkage strain rate ranged from 0.11 (0.01%s(-1)) for Gaenial posterior (GA-P) to 0.59 (0.07) %s(-1) for BFP. Shrinkage stress values ranged from 3.94 (0.40)MPa for TET to 10.45 (0.41)MPa for BFP. The apparent elastic modulus ranged from 153.56 (18.7)MPa for Ever X posterior (EVX) to 277.34 (25.5) MPa for Grandio SO heavy flow (GSO). SIGNIFICANCE The nature of the monomer system determines the amount of the bulk contraction that occurs during polymerization and the resultant stress. Higher values of shrinkage strain and stress were demonstrated by the investigated flowable materials. The bulk-fill materials showed comparable result when compared to the traditional resin-composites.
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Evaluation of polymerization shrinkage in dental restorative experimental composites based: BisGMA/TEGDMA, filled with MMT. J Appl Polym Sci 2016. [DOI: 10.1002/app.43543] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Sampaio CS, Rodrigues RV, Souza-Junior EJ, Freitas AZ, Ambrosano GMB, Pascon FM, Puppin-Rontani RM. Effect of Restorative System and Thermal Cycling on the Tooth-Restoration Interface – OCT Evaluation. Oper Dent 2016; 41:162-70. [DOI: 10.2341/14-344-l] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
SUMMARY
The present study evaluated the tooth/noncarious cervical lesion restoration interface when using different adhesive systems and resin composites, submitted to thermal cycling (TC), using optical coherence tomography (OCT). Noncarious cervical lesion (NCCL) preparations (0.7 mm depth × 2 mm diameter) were performed on 60 human third molars and randomly divided into six groups, according to the adhesive system and resin composite used: group 1 = Adper Single Bond 2 (SB2) + Aelite LS Posterior (AP); group 2 = SB2 + Venus Diamond (VD); group = SB2 + Filtek Z250XT (Z250); group 4 = Clearfil SE Bond (CSE) + AP; group 5 = CSE + VD; group 6 = CSE + Z250. Selective enamel etching was performed for 30 seconds on groups 4, 5, and 6, while groups 1, 2, and 3 were etched for 30 seconds in enamel and 15 seconds in dentin. All groups were evaluated using OCT before and after TC (n=10). Images were analyzed using Image J software; enamel and dentin margins were separately evaluated. Data from OCT were submitted to PROC MIXED for repeated measurements and Tukey Kramer test (α = 0.05). No marginal gaps were observed in etched enamel, either before or after TC, for all adhesive and resin composite systems. A significant interaction was found between adhesive system and TC for the dentin groups; after TC, restorations with CSE showed smaller gaps at the dentin/restoration interface compared with SB2 for all resin composites. Increased gap percentages were noticed after TC compared with the gaps before TC for all groups. In conclusion, TC affected marginal integrity only in dentin margins, whereas etched enamel margins remained stable even after TC. Dentin margins restored with CSE adhesive system showed better marginal adaptation than those restored with SB2. Resin composites did not influence marginal integrity of NCCL restorations.
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Affiliation(s)
- CS Sampaio
- Camila S. Sampaio, DDS, MS, Department of Restorative Dentistry, Dental Materials Area, Piracicaba Dental School, UNICAMP, Piracicaba, Brazil
| | - RV Rodrigues
- Raquel V. Rodrigues, DDS, MS, Department of Restorative Dentistry, Dental Materials Area, Piracicaba Dental School, UNICAMP, Piracicaba, Brazil
| | - EJ Souza-Junior
- Eduardo José Souza-Junior, DDS, MS, PhD, University Center of Varzea Grande (UNIVAG), Dental Materials and Prosthodontics, Santa Helena Cuiabá, Brazil
| | | | - GMB Ambrosano
- Glaucia M. Bovi Ambrosano, DDS, MS, PhD, Community Dentistry Department, Piracicaba Dental School, UNICAMP, Piracicaba, Brazil
| | - FM Pascon
- Fernanda Miori Pascon, DDS, MS, PhD, Department of Pediatric Dentistry, Piracicaba Dental School, UNICAMP, Piracicaba, Brazil
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Vouvoudi EC, Baxevani TI, Sideridou ID. Dental dimethacrylate-based nanohybrid composite Kalore GC: Kinetic study of its light-curing. J Taibah Univ Med Sci 2016. [DOI: 10.1016/j.jtumed.2015.11.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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66
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Effects of a low-shrinkage methacrylate monomer and monoacylphosphine oxide photoinitiator on curing efficiency and mechanical properties of experimental resin-based composites. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2016; 58:487-94. [DOI: 10.1016/j.msec.2015.08.054] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Revised: 07/20/2015] [Accepted: 08/25/2015] [Indexed: 11/21/2022]
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Effect of temperature and humidity on post-gel shrinkage, cusp deformation, bond strength and shrinkage stress – Construction of a chamber to simulate the oral environment. Dent Mater 2015; 31:1523-32. [PMID: 26518338 DOI: 10.1016/j.dental.2015.09.023] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Revised: 04/20/2015] [Accepted: 09/29/2015] [Indexed: 11/20/2022]
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Aljabo A, Abou Neel EA, Knowles JC, Young AM. Development of dental composites with reactive fillers that promote precipitation of antibacterial-hydroxyapatite layers. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2015; 60:285-292. [PMID: 26706532 DOI: 10.1016/j.msec.2015.11.047] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Revised: 10/23/2015] [Accepted: 11/16/2015] [Indexed: 10/22/2022]
Abstract
The study aim was to develop light-curable, high strength dental composites that would release calcium phosphate and chlorhexidine (CHX) but additionally promote surface hydroxyapatite/CHX co-precipitation in simulated body fluid (SBF). 80 wt.% urethane dimethacrylate based liquid was mixed with glass fillers containing 10 wt.% CHX and 0, 10, 20 or 40 wt.% reactive mono- and tricalcium phosphate (CaP). Surface hydroxyapatite layer thickness/coverage from SEM images, Ca/Si ratio from EDX and hydroxyapatite Raman peak intensities were all proportional to both time in SBF and CaP wt.% in the filler. Hydroxyapatite was, however, difficult to detect by XRD until 4 weeks. XRD peak width and SEM images suggested this was due to the very small size (~10 nm) of the hydroxyapatite crystallites. Precipitate mass at 12 weeks was 22 wt.% of the sample CaP total mass irrespective of CaP wt.% and up to 7 wt.% of the specimen. Early diffusion controlled CHX release, assessed by UV spectrometry, was proportional to CaP and twice as fast in water compared with SBF. After 1 week, CHX continued to diffuse into water but in SBF, became entrapped within the precipitating hydroxyapatite layer. At 12 weeks CHX formed 5 to 15% of the HA layer with 10 to 40 wt.% CaP respectively. Despite linear decline of strength and modulus in 4 weeks from 160 to 101 MPa and 4 to 2.4 GPa, respectively, upon raising CaP content, all values were still within the range expected for commercial composites. The high strength, hydroxyapatite precipitation and surface antibacterial accumulation should reduce tooth restoration failure due to fracture, aid demineralised dentine repair and prevent subsurface carious disease respectively.
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Affiliation(s)
- Anas Aljabo
- UCL Eastman Dental Institute, Biomaterials & Tissue Engineering Division, 256 Gray's Inn Road, London WC1X 8LD, United Kingdom
| | - Ensanya A Abou Neel
- UCL Eastman Dental Institute, Biomaterials & Tissue Engineering Division, 256 Gray's Inn Road, London WC1X 8LD, United Kingdom; Division of Biomaterials, Operative Dentistry Department, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia; Biomaterials Department, Faculty of Dentistry, Tanta University, Tanta, Egypt
| | - Jonathan C Knowles
- UCL Eastman Dental Institute, Biomaterials & Tissue Engineering Division, 256 Gray's Inn Road, London WC1X 8LD, United Kingdom
| | - Anne M Young
- UCL Eastman Dental Institute, Biomaterials & Tissue Engineering Division, 256 Gray's Inn Road, London WC1X 8LD, United Kingdom
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69
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Aljabo A, Xia W, Liaqat S, Khan MA, Knowles JC, Ashley P, Young AM. Conversion, shrinkage, water sorption, flexural strength and modulus of re-mineralizing dental composites. Dent Mater 2015; 31:1279-89. [PMID: 26361809 DOI: 10.1016/j.dental.2015.08.149] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Revised: 06/15/2015] [Accepted: 08/14/2015] [Indexed: 10/23/2022]
Abstract
OBJECTIVES Cure, volumetric changes and mechanical properties were assessed for new dental composites containing chlorhexidine (CHX) and reactive calcium phosphate-containing (CaP) to reduce recurrent caries. METHODS 20wt.% of light curable urethane dimethacrylate based liquid was mixed with 80wt.% glass filler containing 10wt.% CHX and 0-40wt.% CaP. Conversion versus depth with 20 or 40s light exposure was assessed by FTIR. Solidification depth and polymerization shrinkage were determined using ISO 4049 and 17304, respectively. Subsequent volume expansion and biaxial flexural strength and modulus change upon water immersion were determined over 4 weeks. Hydroxyapatite precipitation in simulated body fluid was assessed at 1 week. RESULTS Conversion decreased linearly with both depth and CaP content. Average solidification depths were 4.5, 3.9, 3.3, 2.9 and 5.0 with 0, 10, 20, and 40% CaP and a commercial composite, Z250, respectively. Conversions at these depths were 53±2% for experimental materials but with Z250 only 32%. With Z250 more than 50% conversion was achieved only below 1.1mm. Shrinkage was 3% and 2.5% for experimental materials and Z250, respectively. Early water sorption increased linearly, whilst strength and modulus decreased exponentially to final values when plotted versus square root of time. Maximum volumetric expansion increased linearly with CaP rise and balanced shrinkage at 10-20wt.% CaP. Strength and modulus for Z250 decreased from 191 to 158MPa and 3.2 to 2.5GPa. Experimental composites initial strength and modulus decreased linearly from 169 to 139MPa and 5.8 to 3.8GPa with increasing CaP. Extrapolated final values decreased from 156 to 84MPa and 4.1 to 1.7GPa. All materials containing CaP promoted hydroxyapatite precipitation. SIGNIFICANCE The lower surface of composite restorations should both be solid and have greater than 50% conversion. The results, therefore, suggest the experimental composite may be placed in much thicker layers than Z250 and have reduced unbounded cytotoxic monomer. Experimental materials with 10-20wt.% additionally have volumetric expansion to compensate shrinkage, antibacterial and re-mineralizing components and competitive mechanical properties.
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Affiliation(s)
- A Aljabo
- Division of Biomaterials and Tissue Engineering, UCL Eastman Dental Institute, 256 Gray's Inn Road, London WC1X 8LD, UK
| | - W Xia
- Division of Biomaterials and Tissue Engineering, UCL Eastman Dental Institute, 256 Gray's Inn Road, London WC1X 8LD, UK
| | - S Liaqat
- Division of Biomaterials and Tissue Engineering, UCL Eastman Dental Institute, 256 Gray's Inn Road, London WC1X 8LD, UK
| | - M A Khan
- Division of Biomaterials and Tissue Engineering, UCL Eastman Dental Institute, 256 Gray's Inn Road, London WC1X 8LD, UK
| | - J C Knowles
- Division of Biomaterials and Tissue Engineering, UCL Eastman Dental Institute, 256 Gray's Inn Road, London WC1X 8LD, UK
| | - P Ashley
- Department of Paediatric Dentistry, UCL Eastman Dental Institute, 256 Gray's Inn Road, London WC1X 8LD, UK
| | - A M Young
- Division of Biomaterials and Tissue Engineering, UCL Eastman Dental Institute, 256 Gray's Inn Road, London WC1X 8LD, UK.
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Podgórski M, Becka E, Claudino M, Flores A, Shah PK, Stansbury JW, Bowman CN. Ester-free thiol-ene dental restoratives--Part B: Composite development. Dent Mater 2015; 31:1263-70. [PMID: 26360012 DOI: 10.1016/j.dental.2015.08.147] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2015] [Accepted: 08/11/2015] [Indexed: 11/26/2022]
Abstract
OBJECTIVES To assess the performance of thiol-ene dental composites based on selected ester-free thiol-ene formulations. Further, to point out the benefits/drawback of having a hydrolytically stable thiol-ene matrix within a glass filled composite. METHODS Composite samples containing 50-65wt% of functionalized glass microparticles were prepared and photopolymerized in the presence of a suitable visible light photoinitiator. Shrinkage stress measurements were conducted as a function of the irradiation time. Degrees of conversion were measured by FT-IR analysis by comparing the double bond signals before and after photopolymerization. Mechanical tests were carried out on specimens after curing as well as after extended aging in water. Dynamic mechanical analysis was employed to track the changes in storage modulus near body temperature. The properties of the thiol-ene composites were compared with those of the BisGMA/TEGDMA control. RESULTS Depending on the resin type, similar or higher conversions were achieved in thiol-ene composites when compared to the dimethacrylate controls. At comparable conversions, lower shrinkage stress values were achieved. Although exhibiting lower initial elastic moduli, the thiol-ene composites' flexural strengths were found to be comparable with the controls. Contrary to the control, the mechanical properties of the ester-free thiol-ene composites were shown to be unaffected by extensive aging in water and at least equaled that of the control after aging in water for just five weeks. SIGNIFICANCE Employing non-degradable step-growth networks as organic matrices in dental composites will provide structurally uniform, tough materials with extended service time.
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Affiliation(s)
- Maciej Podgórski
- Department of Chemical and Biological Engineering, University of Colorado, 3415 Colorado Ave, JSC Biotech Building, Boulder, CO 80309, USA; Department of Polymer Chemistry, Faculty of Chemistry, MCS University, Gliniana St. 33, 20-614 Lublin, Poland
| | - Eftalda Becka
- Department of Chemical and Biological Engineering, University of Colorado, 3415 Colorado Ave, JSC Biotech Building, Boulder, CO 80309, USA
| | - Mauro Claudino
- Department of Chemical and Biological Engineering, University of Colorado, 3415 Colorado Ave, JSC Biotech Building, Boulder, CO 80309, USA
| | - Alexander Flores
- Department of Chemical and Biological Engineering, University of Colorado, 3415 Colorado Ave, JSC Biotech Building, Boulder, CO 80309, USA
| | - Parag K Shah
- Department of Chemical and Biological Engineering, University of Colorado, 3415 Colorado Ave, JSC Biotech Building, Boulder, CO 80309, USA
| | - Jeffrey W Stansbury
- Department of Chemical and Biological Engineering, University of Colorado, 3415 Colorado Ave, JSC Biotech Building, Boulder, CO 80309, USA; Department of Craniofacial Biology, School of Dental Medicine, University of Colorado, Denver, Anschutz Medical Campus, Mail Stop 8310, 12800E. 19th Avenue, Aurora, CO 80045, USA
| | - Christopher N Bowman
- Department of Chemical and Biological Engineering, University of Colorado, 3415 Colorado Ave, JSC Biotech Building, Boulder, CO 80309, USA.
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Tauböck TT, Tarle Z, Marovic D, Attin T. Pre-heating of high-viscosity bulk-fill resin composites: effects on shrinkage force and monomer conversion. J Dent 2015; 43:1358-64. [PMID: 26232610 DOI: 10.1016/j.jdent.2015.07.014] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Revised: 07/22/2015] [Accepted: 07/27/2015] [Indexed: 10/23/2022] Open
Abstract
OBJECTIVES To investigate the influence of pre-heating of high-viscosity bulk-fill composite materials on their degree of conversion and shrinkage force formation. METHODS Four bulk-fill composite materials (Tetric EvoCeram Bulk Fill-TECBF, x-tra fil-XF, QuixFil-QF, SonicFill-SF) and one conventional nano-hybrid resin composite (Tetric EvoCeram-TEC) were used. The test materials were either kept at room temperature or pre-heated to 68°C by means of a commercial heating device, before being photoactivated with a LED curing unit for 20s at 1170mW/cm(2). Shrinkage forces (n=5) of 1.5-mm-thick specimens were recorded in real-time for 15min inside a temperature-controlled chamber at 25°C (simulating intraoral temperature after rubber dam application) with a custom-made stress analyzer. Degree of conversion (n=5) was determined at the bottom of equally thick (1.5mm) specimens using Fourier transform infrared spectroscopy. Data were analyzed with Student's t-test, ANOVA and Tukey's HSD post-hoc test (α=0.05). RESULTS Composite pre-heating significantly increased the degree of conversion of TECBF, but had no effect on monomer conversion of the other materials investigated. For each of the test materials, pre-heated composite generated significantly lower shrinkage forces than room-temperature composite. At both temperature levels, TECBF created the significantly highest shrinkage forces, and QF caused significantly higher shrinkage forces than both XF and TEC. CONCLUSIONS Both the composite material and the pre-cure temperature affect shrinkage force formation. Pre-heating of bulk-fill and conventional restorative composites prior to photoactivation decreases polymerization-induced shrinkage forces without compromising the degree of conversion. CLINICAL SIGNIFICANCE Composite pre-heating significantly reduces shrinkage force formation of high-viscosity bulk-fill and conventional resin composites, while maintaining or increasing the degree of monomer conversion, dependent upon the specific composite material used.
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Affiliation(s)
- Tobias T Tauböck
- Department of Preventive Dentistry, Periodontology and Cariology, Center for Dental Medicine, University of Zurich, Plattenstrasse 11, CH-8032 Zurich, Switzerland.
| | - Zrinka Tarle
- Department of Endodontics and Restorative Dentistry, School of Dental Medicine, University of Zagreb, Gunduliceva 5, HR-10000 Zagreb, Croatia
| | - Danijela Marovic
- Department of Endodontics and Restorative Dentistry, School of Dental Medicine, University of Zagreb, Gunduliceva 5, HR-10000 Zagreb, Croatia
| | - Thomas Attin
- Department of Preventive Dentistry, Periodontology and Cariology, Center for Dental Medicine, University of Zurich, Plattenstrasse 11, CH-8032 Zurich, Switzerland
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Al Sunbul H, Silikas N, Watts DC. Resin-based composites show similar kinetic profiles for dimensional change and recovery with solvent storage. Dent Mater 2015. [PMID: 26220777 DOI: 10.1016/j.dental.2015.06.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
OBJECTIVES To investigate the sorption, solubility, mass change and hygroscopic expansion (solvent swelling) of resin-composites after long term storage in different solvents. METHODS Eight materials were studied: two bulk-fill flowable materials (SDR and Venus bulk fill, V-BF), a packable bulk-fill material (Tetric Evoceram bulk-fill, TET-BF), a fiber reinforced material (Ever X posterior, EVX), a nano-hybrid conventional material (Tetric Evoceram, TET) and micro-hybrid conventional materials (G-aenial anterior, GA-P and posterior, GA-A). Three groups of disk shaped specimens were prepared using split stainless steel molds. Each group was stored, respectively, in: water, 75% ethanol/water and methyl ethyl ketone (MEK). The total storage time was 180 d plus a reconditioning time of 120 d. A non-contact laser scanning micrometer was used to measure the diametral changes. RESULTS Significant differences were found in the sorption and solubility of the materials. Generally, MEK stored specimens had the highest values followed by 75% ethanol/water then water. A similar trend was found with the mass and volume changes (except for EVX). V-BF showed the highest sorption (98.1μg/mm(3)) and solubility (10μg/mm(3)) after MEK storage. Mass and volume changes showed near-linear correlation, with high Pearson coefficients (0.86-0.99). SIGNIFICANCE Generally the materials were most greatly affected by MEK storage compared to the other two solvents. The glass-fiber-reinforced EVX, however, was most affected by water immersion. The pattern of change/recovery behavior of the materials, during solvent challenge, was similar to the pattern of viscoelastic creep/recovery behavior of resin-composite materials.
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Affiliation(s)
- Hanan Al Sunbul
- School of Dentistry, The University of Manchester, Manchester, UK; College of Dentistry, King Saud University, Riyadh, Saudi Arabia
| | - Nick Silikas
- School of Dentistry, The University of Manchester, Manchester, UK.
| | - David C Watts
- School of Dentistry, The University of Manchester, Manchester, UK; Photon Science Institute, The University of Manchester, Manchester, UK.
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Sideridou ID, Vouvoudi EC, Keridou IV. Sorption characteristics of oral/food simulating liquids by the dental light-cured nanohybrid composite Kalore GC. Dent Mater 2015; 31:e179-89. [PMID: 26093782 DOI: 10.1016/j.dental.2015.06.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2015] [Revised: 04/01/2015] [Accepted: 06/01/2015] [Indexed: 10/23/2022]
Abstract
OBJECTIVE This work presents the results obtained from the study of sorption/desorption process of some food/oral simulating liquids (FSLs) by the new marketed dental light-cured nanohybrid composite Kalore GC. METHODS The sorption/desorption process followed is recommended by ISO 4049:2009. The samples were immersed in various liquids proposed by ADA as FSLs, such as H2O, artificial saliva, EtOH, EtOH/H2O solution (75vol%) or C7H16, while the mass change for totally 30 days was recorded on defined time intervals. Afterwards the samples were put in dry desiccators at 37°C for the study of desorption process. RESULTS The weight percentage of sorption of the above mentioned FSLs by Kalore GC was determined; also the wt% of the desorbed liquid, the diffusion coefficient of sorption and desorption, the wt% solubility and the % volume increase due to the liquid sorption. SIGNIFICANCE The sorption characteristics of a dental composite depend both on composite structure and liquid. Ethanol/water and ethanol showed the highest effect on the determined characteristics. Then, the water and SAGF(®) saliva follows and finally the heptane solvent.
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Affiliation(s)
- Irini D Sideridou
- Laboratory of Organic Chemical Technology, Department of Chemistry, Aristotle University of Thessaloniki, Thessaloniki GR-54 124, Macedonia, Greece.
| | - Evangelia C Vouvoudi
- Laboratory of Organic Chemical Technology, Department of Chemistry, Aristotle University of Thessaloniki, Thessaloniki GR-54 124, Macedonia, Greece
| | - Ina V Keridou
- Laboratory of Organic Chemical Technology, Department of Chemistry, Aristotle University of Thessaloniki, Thessaloniki GR-54 124, Macedonia, Greece
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Wang R, Zhang M, Liu F, Bao S, Wu T, Jiang X, Zhang Q, Zhu M. Investigation on the physical-mechanical properties of dental resin composites reinforced with novel bimodal silica nanostructures. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2015; 50:266-73. [PMID: 25746270 DOI: 10.1016/j.msec.2015.01.090] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Revised: 01/05/2015] [Accepted: 01/30/2015] [Indexed: 12/25/2022]
Abstract
The aim of this study was to investigate the influence of bimodal silica nanostructures comprising of SiO2 nanoparticles (SiO2 NPs, ~70 nm) and SiO2 nanoclusters (SiO2 NCs, 0.07-2.70 μm) on physical-mechanical properties of resin-based composites (RBCs). SiO2 NPs and SiO2 NCs were prepared with the Stöber method and the coupling reaction, respectively, then silanized and employed as fillers to construct RBCs using a mixture of bisphenol A glycerolate dimethacrylate (Bis-GMA) and tri(ethylene glycol) dimethacrylate (TEGDMA) as the organic matrix. Results showed that the properties of RBCs were influenced by the filler ratios of bimodal silica nanostructures, and the appropriate amount of SiO2 NPs could effectively increase the activating light efficiency and filler packing density of RBCs. Among all experimental RBCs, RBC 50-20 (SiO2 NPs:SiO2 NCs=50:20, wt/wt) presented the highest degree of conversion (71.6±1.1%), the lowest polymerization shrinkage (2.6±0.1%), and the enhanced flexural strength (104.8±4.4 MPa), flexural modulus (6.2±0.3 GPa), and compressive strength (205.8±14.3 MPa), which were improved by 44%, 19%, 28%, 48%, and 42% in comparison with those of RBC 0-60 (SiO2 NPs:SiO2 NCs=0:60, wt/wt), respectively. Besides, in vitro cytotoxicity evaluation of RBC 50-20 indicated its acceptable cytotoxicity. Although the best performance was achieved by commercial Z350 XT, the introduction of bimodal silica nanostructures might provide the enhanced physical-mechanical properties of RBCs, compared with those of RBC 0-60 reinforced with unimodal SiO2 NCs.
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Affiliation(s)
- Ruili Wang
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Material Science and Engineering, Donghua University, Shanghai 201620, PR China
| | - Maolin Zhang
- Department of Oral and Maxillofacial Surgery, Shanghai 9th People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Stomatology, Shanghai 200011, PR China
| | - Fengwei Liu
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Material Science and Engineering, Donghua University, Shanghai 201620, PR China
| | - Shuang Bao
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Material Science and Engineering, Donghua University, Shanghai 201620, PR China
| | - Tiantian Wu
- Department of General Dentistry, Shanghai 9th People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Stomatology, Shanghai 200011, PR China
| | - Xiaoze Jiang
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Material Science and Engineering, Donghua University, Shanghai 201620, PR China
| | - Qinghong Zhang
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Material Science and Engineering, Donghua University, Shanghai 201620, PR China
| | - Meifang Zhu
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Material Science and Engineering, Donghua University, Shanghai 201620, PR China.
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Aguiar TR, de Oliveira M, Arrais CA, Ambrosano GM, Rueggeberg F, Giannini M. The effect of photopolymerization on the degree of conversion, polymerization kinetic, biaxial flexure strength, and modulus of self-adhesive resin cements. J Prosthet Dent 2015; 113:128-34. [DOI: 10.1016/j.prosdent.2014.09.011] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Revised: 08/30/2014] [Accepted: 09/02/2014] [Indexed: 11/30/2022]
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Dejak B, Młotkowski A. A comparison of stresses in molar teeth restored with inlays and direct restorations, including polymerization shrinkage of composite resin and tooth loading during mastication. Dent Mater 2014; 31:e77-87. [PMID: 25544104 DOI: 10.1016/j.dental.2014.11.016] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Revised: 06/11/2014] [Accepted: 11/26/2014] [Indexed: 11/17/2022]
Abstract
UNLABELLED Polymerization shrinkage of composites is one of the main causes of leakage around dental restorations. Despite the large numbers of studies there is no consensus, what kind of teeth reconstruction--direct or indirect composite restorations are the most beneficial and the most durable. OBJECTIVE The aim was to compare equivalent stresses and contact adhesive stresses in molar teeth with class II MOD cavities, which were restored with inlays and direct restorations (taking into account polymerization shrinkage of composite resin) during simulated mastication. METHOD The study was conducted using the finite elements method with the application of contact elements. Three 3D models of first molars were created: model A was an intact tooth; model B--a tooth with a composite inlay, and model C--a tooth with a direct composite restoration. Polymerization linear shrinkage 0.7% of a direct composite restoration and resin luting cement was simulated (load 1). A computer simulation of mastication was performed (load 2). In these 2 situations, equivalent stresses according to the modified von Mises criterion (mvM) in the materials of mandibular first molar models with different restorations were calculated and compared. Contact stresses in the luting cement-tooth tissue adhesive interface around the restorations were also assessed and analyzed. RESULTS Equivalent stresses in a tooth with a direct composite restoration (the entire volume of which was affected by polymerization shrinkage) were many times higher than in the tooth restored with a composite inlay (where shrinkage was present only in a thin layer of the luting cement). In dentin and enamel the stress values were 8-14 times higher, and were 13 times higher in the direct restoration than in the inlay. Likewise, contact stresses in the adhesive bond around the direct restoration were 6.5-7.7 times higher compared to an extraorally cured restoration. In the masticatory simulation, shear contact stresses in the adhesive bond around the direct composite restoration reached the highest values 32.8 MPa and significantly exceeded the shear strength of the connection between the resin luting cement and the tooth structure. SIGNIFICANCE Equivalent stresses in the tooth structures restored with inlays and in the restoration material itself and contact stresses at the tooth-luting cement adhesive interface are many times lower compared to teeth with direct composite restorations. Teeth with indirect restorations are potentially less susceptible to damage compared to those with direct restorations. Composite inlays also ensure a better seal compared to direct restorations. Polymerization shrinkage determines stress levels in teeth with direct restorations, while its impact on adhesion in indirectly restored teeth is insignificant.
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Affiliation(s)
- Beata Dejak
- Department of Prosthetic Dentistry, Medical University of Łódź, Łódź, Poland.
| | - Andrzej Młotkowski
- Department of Strength of Materials and Structures, Technical University of Łódź, Łódź, Poland
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Water sorption and solubility of core build-up materials. Dent Mater 2014; 30:e324-9. [DOI: 10.1016/j.dental.2014.08.374] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Revised: 08/07/2014] [Accepted: 08/08/2014] [Indexed: 11/19/2022]
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78
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Al Khuraif AAA. An in vitro evaluation of wear and surface roughness of particulate filler composite resin after tooth brushing. Acta Odontol Scand 2014; 72:977-83. [PMID: 25220522 DOI: 10.3109/00016357.2014.933251] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE To evaluate the influence of tooth brushing on wear and surface roughness of four different particulate filler composite resins. MATERIALS AND METHODS Six specimens (2 mm thick and 8 mm in diameter) of each tested material (Filtek Z250-Microhybrid, SpectrumTPH3-Submicron hybrid, Filtek Z350XT Nanofiller and Filtek P90- Microhybrid) were prepared according to the manufacturer's directions. A brushing sequence of 5000, 10,000 and 20,000 cycles was performed for all the samples. A non-contact profilometer was used to determine average surface roughness (Ra) and wear of the material assessed using an analytic electronic balance at baseline and each cycle interval. The data obtained were analyzed using one-way ANOVAs and post-hoc multiple comparison tests. Paired t-test was used for comparisons between cycle intervals for each material. Analyses with scanning electron microscopy (SEM) were also performed. RESULTS The resin composite Filtek P 90 presented an increase in percentage weight loss after final toothbrushing cycles over the rest of the materials. Brushing significantly increased roughness (Ra) for all composites. Filtek Z250, after brushing, was significantly rougher than the other resins followed by Filtek P 90, Spectrum TPH 3 and Filtek Z350 XT. However, SEM images indicated severe change in surface topography of 'sub-micron hybrid' specimen compared to each other after tooth brushing. CONCLUSIONS Wear and surface roughness increased with each cycle interval for all the materials and one composite resin demonstrated a higher increase in surface roughness than the other three tested brands of composite resins. Not much difference was observed in the weight loss between tested samples.
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Affiliation(s)
- Abdul Aziz A Al Khuraif
- Dental Health Department, College of Applied Medical Sciences, King Saud University , Riyadh , Saudi Arabia
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79
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Ferracane JL, Pfeifer CS, Hilton TJ. Microstructural Features of Current Resin Composite Materials. ACTA ACUST UNITED AC 2014. [DOI: 10.1007/s40496-014-0029-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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80
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Gonulol N, Ozer S, Sen Tunc E. Water Sorption, Solubility, and Color Stability of Giomer Restoratives. J ESTHET RESTOR DENT 2014; 27:300-6. [PMID: 25145876 DOI: 10.1111/jerd.12119] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVES This study compared the color stability, water sorption, and solubility of a giomer composite and two nanohybrid composite resins. MATERIALS AND METHODS Disc-shaped specimens (1-mm thickness × 15-mm diameter) of a giomer (Beautifil II, Shofu, Kyoto, Japan) and two nanohybrid (Filtek Z550, 3M ESPE, St. Paul, MN, USA; Tetric N-Ceram, Ivoclar Vivadent, Schaan, Liechtenstein) composites (N = 10) were prepared. Baseline color measurements were taken, and specimens were immersed in water for 28 days. Following immersion, color values were remeasured, and color-change values (ΔE) were calculated. Water sorption and solubility were assessed by mass gain or loss after storage in water for 28 days. Data were analyzed with one-way analysis of variance and Tukey's post-hoc tests (p = 0.05). Pearson's correlation test was used to assess possible correlations between water sorption and solubility, water sorption and color stability, and solubility and color stability (p = 0.05). RESULTS Water sorbtion (%) and color change (ΔE) varied significantly among groups, with Beautifil II exhibiting the highest values (p < 0.001). No statistically significant differences were observed in water solubility values among the groups (p = 0.661); however, a linear, positive correlation was detected between solubility and discoloration (r = 0.368, p = 0.046). CONCLUSION Water sorption and discoloration values of the giomer composite group were significantly higher than those of the nanohybrids tested. CLINICAL SIGNIFICANCE The high levels of water sorption and discoloration of giomer composites are likely to have an adverse effect on esthetic restorations.
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Affiliation(s)
- Nihan Gonulol
- Department of Restorative Dentistry, Faculty of Dentistry, Ondokuz Mayıs University, Samsun, Turkey
| | - Sezin Ozer
- Department of Pediatric Dentistry, Faculty of Dentistry, Ondokuz Mayıs University, Samsun, Turkey
| | - Emine Sen Tunc
- Department of Pediatric Dentistry, Faculty of Dentistry, Ondokuz Mayıs University, Samsun, Turkey
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81
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Schmalz G, Gröppl F, Hiller KA, Galler KM. Three-Dimensional Human Cell Cultures for Cytotoxicity Testing of Dental Filling Materials. Acta Stomatol Croat 2014; 48:99-108. [PMID: 27688353 PMCID: PMC4872801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Accepted: 06/16/2014] [Indexed: 06/06/2023] Open
Abstract
OBJECTIVES So far, bovine immortalized pulp cells have been used as three dimensional cultures for cytotoxicity testing of filling materials in the dentin barrier test (DBT). In this study, the use of human pulp-derived cells was evaluated, which would better simulate the clinical situation, and a composite material with a new resin base was tested. MATERIALS AND METHODS SV40-transfected human pulp cells (tHPC) were cultured in hydrogels (fibrin, peptide, collagen) and mechanical properties and cell viability (MTT or WST-1) were determined. For cell cultures in collagen, a four week - proliferation assay was performed (WST-1). After 14 days of three-dimensional culture in collagen, tHPC were introduced into the DBT with 200 µm dentin disks. After a 24-hour incubation under perfusion (0.3 ml/h), the following materials were applied according to the manufacturers' instructions (1) President (Coltene): negative (non-toxic) control, (2) CaGPG14 (ISO 7405): positive (toxic) control, (3) Tetric EvoCeram (Ivoclar Vivadent) with Clearfil SEBond (Kuraray, reference material), (4) N´Durance (Sepodont, test material), (5) N´Durance with Clearfil SEBond. Cell viability was determined after 24-hour incubation (WST-1). The percentage of relative viability was calculated (negative control=100%) and statistically analyzed (Kruskal-Wallis-test, p<0.05). RESULTS Fibrin and peptide gels had insufficient mechanical properties for the DBT Collagen and appeared suitable for three-dimensional cell culture of tHPC for up to 21 days. The cultures could be transferred to the DBT device and results for controls were similar to previous tests with bovine cells. The DBT using tHPC in the collagen showed no statistically significant difference between the test material with and without the adhesive and the reference resin composite. CONCLUSIONS tHPC in collagen can replace bovine cells in the DBT. The tested filling material is not likely to cause pulp damage, if the pulp is covered by an intact dentin layer.
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Affiliation(s)
- Gottfried Schmalz
- Department of Operative Dentistry and Periodontology, University of Regensburg, Germany
- School of Dental Medicine (ZMK Bern), University of Bern, Switzerland
| | | | - Karl-Anton Hiller
- Department of Operative Dentistry and Periodontology, University of Regensburg, Germany
| | - Kerstin M. Galler
- Department of Operative Dentistry and Periodontology, University of Regensburg, Germany
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82
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Characterization of a low shrinkage dental composite containing bismethylene spiroorthocarbonate expanding monomer. Int J Mol Sci 2014; 15:2400-12. [PMID: 24518683 PMCID: PMC3958858 DOI: 10.3390/ijms15022400] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Revised: 01/15/2014] [Accepted: 01/24/2014] [Indexed: 02/05/2023] Open
Abstract
In this study, a novel dental composite based on the unsaturated bismethylene spiroorthocarbonate expanding monomer 3,9-dimethylene-1,3,5,7-tetraoxa-spiro[5,5]undecane (BMSOC) and bisphenol-S-bis(3-meth acrylate-2-hydroxypropyl)ether (BisS-GMA) was prepared. CQ (camphorquinone) of 1 wt % and DMAEMA (2-(dimethylamino)ethyl methacrylate) of 2 wt % were used in a photoinitiation system to initiate the copolymerization of the matrix resins. Distilled water contact angle measurements were performed for the wettability measurement. Degree of conversion, volumetric shrinkage, contraction stress and compressive strength were measured using Fourier Transformation Infrared-FTIR spectroscopy, the AccuVol and a universal testing machine, respectively. Within the limitations of this study, it can be concluded that the resin composites modified by bismethylene spiroorthocarbonate and BisS-GMA showed a low volumetric shrinkage at 1.25% and a higher contact angle. The lower contraction stress, higher degree of conversion and compressive strength of the novel dental composites were also observed.
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83
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Experimental and FE displacement and polymerization stress of bonded restorations as a function of the C-Factor, volume and substrate stiffness. J Dent 2014; 42:140-8. [DOI: 10.1016/j.jdent.2013.11.016] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Revised: 11/18/2013] [Accepted: 11/25/2013] [Indexed: 11/17/2022] Open
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84
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Walter R, Boushell LW, Heymann HO, Ritter AV, Sturdevant JR, Wilder AD, Chung Y, Swift EJ. Three-Year Clinical Evaluation of a Silorane Composite Resin. J ESTHET RESTOR DENT 2013; 26:179-90. [DOI: 10.1111/jerd.12077] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ricardo Walter
- Department of Preventive and Restorative Sciences; University of Pennsylvania School of Dental Medicine; Philadelphia PA USA
| | - Lee W. Boushell
- Department of Operative Dentistry; University of North Carolina at Chapel Hill; Chapel Hill NC USA
| | - Harald O. Heymann
- Department of Operative Dentistry; University of North Carolina at Chapel Hill; Chapel Hill NC USA
| | - Andre V. Ritter
- Department of Operative Dentistry; University of North Carolina at Chapel Hill; Chapel Hill NC USA
| | - John R. Sturdevant
- Department of Operative Dentistry; University of North Carolina at Chapel Hill; Chapel Hill NC USA
| | - Aldridge D. Wilder
- Department of Operative Dentistry; University of North Carolina at Chapel Hill; Chapel Hill NC USA
| | - Yunro Chung
- Department of Biostatistics; University of North Carolina Gillings School of Global Public Health; Chapel Hill NC USA
| | - Edward J. Swift
- Department of Operative Dentistry; University of North Carolina at Chapel Hill; Chapel Hill NC USA
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85
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Park J, Ferracane J. Water Aging Reverses Residual Stresses in Hydrophilic Dental Composites. J Dent Res 2013; 93:195-200. [DOI: 10.1177/0022034513513905] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Dental composites develop residual stresses during polymerization due to shrinkage. These stresses may change with time because of relaxation and water sorption in the oral environment. This phenomenon is likely dependent on the composition of the materials, specifically their hydrophilic characteristics, and could result in deleterious stresses on restorative materials and tooth structure. The purpose of this experiment was to use the thin ring-slitting method to compare the residual stress generated within composite materials of varying hydrophilicity when aged in wet and dry conditions after polymerization. Water sorption, solubility, elastic modulus, and residual stresses were measured in 6 commercial composites/cements aged in water and dry conditions. The self-adhesive resin cement showed the highest water sorption and solubility. All composites showed initial residual contraction stresses, which were maintained when aged dry. Residual stresses in 2 of the self-adhesive cements and the polyacid-modified composite aged in wet conditions resulted in a net expansion. This experiment verified that residual shrinkage stresses in dental composites can be reversed during aging in water, resulting in a net expansion, with the effect directly related to their hydrophilic properties.
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Affiliation(s)
- J.W. Park
- Department of Conservative Dentistry, College of Dentistry, Yonsei University, Seoul, Korea
| | - J.L. Ferracane
- Department of Restorative Dentistry, Division of Biomaterials and Biomechanics, School of Dentistry, Oregon Health and Science University, Portland, OR, USA
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86
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FT-Raman spectroscopy: a useful tool in measuring resin composite degradation? Future Med Chem 2013; 5:1599-601. [DOI: 10.4155/fmc.13.119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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87
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Mechanical and physical properties of silorane and methacrylate-based composites. J Dent 2013; 41:732-9. [DOI: 10.1016/j.jdent.2013.05.012] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2013] [Revised: 05/19/2013] [Accepted: 05/20/2013] [Indexed: 11/20/2022] Open
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88
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Yamasaki LC, De Vito Moraes AG, Barros M, Lewis S, Francci C, Stansbury JW, Pfeifer CS. Polymerization development of "low-shrink" resin composites: Reaction kinetics, polymerization stress and quality of network. Dent Mater 2013; 29:e169-79. [PMID: 23849746 DOI: 10.1016/j.dental.2013.04.021] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2012] [Revised: 02/28/2013] [Accepted: 04/25/2013] [Indexed: 10/26/2022]
Abstract
OBJECTIVES To evaluate "low-shrink" composites in terms of polymerization kinetics, stress development and mechanical properties. METHODS "Low-shrink" materials (Kalore/KAL, N'Durance/NDUR, and Filtek P90/P90) and one control (Esthet X HD/EHD) were tested. Polymerization stress (PS) was measured using the Instron 5565 tensometer. Volumetric shrinkage (VS) was determined by the ACTA linometer. Elastic modulus (E) and flexural strength (FS) were obtained by a three-point bending test. Degree of conversion (DC) and polymerization rate (Rp) were determined by NIR spectroscopy (6165cm(-1) for dimethacrylates; 4156 and 4071cm(-1) for P90). Photopolymerization was performed at 740mW/cm(2)×27s. Glass transition temperature (Tg), degree of heterogeneity and crosslink density were obtained in a DMA for the fully cured specimens. Analysis of extracts was done by (1)H NMR. Data were analyzed with one-way ANOVA/Tukey's test (α=0.05). RESULTS The control presented the highest shrinkage and Tg. P90 showed the highest modulus, and NDUR demonstrated the highest conversion. The polymerization rates were comparable for all materials. NDUR and KAL had the highest and the lowest network homogeneity, respectively. The multifunctional P90 had the highest crosslink density, with no difference between other composites. The control had the greatest stress development, similar to NDUR. Crosslinking density and polymer network homogeneity were influenced by degree of conversion and monomer structure. SIGNIFICANCE Not all "low-shrink" composites reduced polymerization stress. P90 and NDUR had no leachable monomers, which was also a function of high crosslinking (P90) and high conversion (NDUR).
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Affiliation(s)
- Lilyan C Yamasaki
- Department of Biomaterials and Oral Biology, University of São Paulo, School of Dentistry, São Paulo, SP, Brazil.
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Wei YJ, Silikas N, Zhang ZT, Watts DC. The relationship between cyclic hygroscopic dimensional changes and water sorption/desorption of self-adhering and new resin-matrix composites. Dent Mater 2013; 29:e218-26. [PMID: 23830294 DOI: 10.1016/j.dental.2013.05.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2012] [Revised: 05/15/2013] [Accepted: 05/23/2013] [Indexed: 10/26/2022]
Abstract
OBJECTIVES This study evaluated the relationship between mass changes and hygroscopic dimensional changes during water sorption/desorption cycles in new resin composites. METHODS A silorane posterior composite (Filtek(®) Silorane, FS), two micro-fine hybrid composites (GC Gradia Direct Anterior, GDA; GC Gradia Direct Posterior, GDP), a universal composite (GC Kalore, GCK), and a self-adhering flowable composite (Vertise(®) Flow, VF) were evaluated. 25 (n=5) disk specimens (15mm×2mm) were prepared according to ISO 4049. Water sorption was measured gravimetrically. Hygroscopic expansions were measured by a laser micrometer regularly during 150 d water storage and 40 d recondition periods, all at 37°C. Data were analyzed by repeated measures ANOVA, one-way ANOVA and Tukey's post hoc test (p<0.05). RESULTS Mass changes after 150 d water immersion ranged from 0.68% (±0.02) for FS to 2.83% (±0.11) for VF and the corresponding hygroscopic expansions were from 0.74% (±0.05) for FS to 4.79% (±0.18) for VF. The differences were significant for all materials (p<0.001), except mass changes between GCK and GDP, as well as hygroscopic changes between GCK and GDA. The relationship between hygroscopic expansions and mass changes was initially non-linear and then tended toward linear behavior. But at the late stage of water sorption the hygroscopic expansion of GCK and VF was slightly sigmoidal with respect to their mass changes. SIGNIFICANCE Relationships between hygroscopic expansion and mass change were determined for some diverse resin-matrix composites. The initial non-linearity for all materials suggests a lower expansion rate due to occupancy of internal free volume by water ingress. The silorane composite FS showed statistically the lowest mass change and hygroscopic dimensional change.
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Affiliation(s)
- Yong-Jie Wei
- Department of Prosthodontics, School of Stomatology, Capital Medical University, Beijing, PR China.
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